3,4,5-trihydroxybenzoic acid

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

not specified

Remarks:

published data without specification of GLP compliance

Specific details on test material used for the study:

Gallic acid (98 % purity) was obtained as dry powder from Acros Organics (no. 410860010).

Analytical monitoring:

no

Vehicle:

yes

Remarks:

standardized water

Details on test solutions:

A stock solution of 8 g/L was prepared in standardized water (OECD 1992) and used for serial dilution during exposure experiments.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

Wild-type zebrafish (D. rerio, TU strain) with similar length and age (2±1 cm, 3 months old) were provided by GIS AMAGEN (UMS 3504 CNRS/UMS 1374 INRA, Gif-sur-Yvette, France). They were acclimatized for 2 weeks in aerated glass containers filled with artificially reconstituted water (24±2 °C; 12:12-h light/dark photoperiod) (OECD 1992). They were fed twice daily with commercial pellets (BioMar, France) and twice weekly with freshly hatched Artemia nauplii. During the acclimation period, no mortality neither abnormal behaviour were reported, thereby meeting the batch validity criteria for further experiments (Directive 2001/59/CE; OECD 1992).

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Nominal and measured concentrations:

preliminary: increasing doses arranged in a geometric series up to 1000 mg/L of test substance.
definitive assays: 5, 10, 20, 40 and 100 mg/L

Details on test conditions:

Briefly, a series of preliminary range-finding tests were conducted using respectively gallic and pelargonic acids. For gallic acid, given the absence of any toxicological data regarding fish mortality, animals were exposed to increasing doses arranged in a geometric series up to 1000 mg/L of test substance. Definitive assays for this compound were performed in order to confirm that the LC50 was greater than 100 mg/L, i.e. that the substance was practically non-toxic to fish according to general guidance document (US EPA 1992). Additional exposure to lower concentrations of 5, 10, 20 and 40 mg/L of gallic acid were also set up during the definitive assays so as to get insights into potential dosedependent sublethal effects of the polyphenolic compound
following biomarker assessment (antioxidant enzymes and GST activities). During definitive assays, a group of 10 fish was randomly distributed in each glass tank (i.e. less than 1 g fish/L of test solution according to the recommendations of OECD 1992),
containing appropriate compound concentration. This procedure was repeated in triplicates for each concentration including control groups (non-exposed fish in tanks containing only freshwater). Fish were not fed 24 h before the beginning of experiments and during the 4 days of toxicity assessment. They were exposed to test substances in static conditions without any replacement of solutions throughout the duration of the study (OECD 1992). Temperature, pH and dissolved oxygen were checked daily. Number of dead fish (immediately removed fromtanks) was recorded at 24, 48, 72 and 96 h so as to determine the acute toxicity at each time-point expressed as mean lethal concentration (LC50).

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Details on results:

During the range-finding tests, no mortality occurred from 24 to 72 h of fish exposure. On the fourth day of experiment, three fish died at the highest concentration of 1000 mg/L, leading to a geometrical mean calculation for 96-h LC50 of 707 mg/L. Definitive assays confirmed that the LC50 was higher than 100 mg/L, without any visible changes in fish behaviour that could be noticed during all the exposure period. Therefore, according to regulatory guidance (US 2012), gallic acid could be considered as practically non-toxic to the zebrafish.

Validity criteria fulfilled:

not specified

Conclusions:

The acute toxicity assessment of gallic acid indicated 96-h LC50 higher than 100 mg/L in zebrafish. During the range-finding tests, no mortality occurred from 24 to 72 h of fish exposure. On the fourth day of experiment, three fish died at the highest concentration of 1000 mg/L, leading to a geometrical mean calculation for 96-h LC50 of 707 mg/L.

Executive summary:

The acute toxicity assessment of gallic acid indicated 96-h LC50 higher than 100 mg/L in zebrafish. During the range-finding tests, no mortality occurred from 24 to 72 h of fish exposure. On the fourth day of experiment, three fish died at the highest concentration of 1000 mg/L, leading to a geometrical mean calculation for 96-h LC50 of 707 mg/L.

Description of key information

The acute toxicity assessment of gallic acid indicated 96-h LC50 higher than 100 mg/L in zebrafish.

During the range-finding tests, no mortality occurred from 24 to 72 h of fish exposure. On the fourth day of experiment, three fish died at the highest concentration of 1000 mg/L, leading to a geometrical mean calculation for 96-h LC50 of 707 mg/L.

Based on these endpoints, gallic acid is not classified for aquatic hazards.